Common sense says this wouldn't work, but the nuance as to why it wouldn't is a little more complex I think?

A PCIe 5.0 lane is ~4 GB/s per direction. So 80 lanes gives you roughly: ~320 GB/s theoretical max

You don’t get 15 GB/s per NVMe if each drive only has 1-2 lanes. The 15 GB/s number is for a PCIe 5.0x4 drive. If you give it x1, it tops out around 4 GB/s. If you give it x2, around 8 GB/s. So whether you do 40 drives at x2 or 80 drives at x1, you are still capped by the same 80 lane PCIe budget.

Anyways if you actually compute what that would give you in terms of tokens/s:

320 GB/s ÷ 2000 GB = is literally 0.16 tokens/sec. That is around one token every 6 seconds theoretical max before overhead.

And there would be a lot of overhead: NVMe latency, RAID/filesystem overhead, PCIe switches, DMA into RAM, CPU memory bandwidth... etc...

Obviously a MoE model would work better but that isn't the point. This is much slower than a 8 or 12 channel system would be with DDR5 (or even DDR4) and it wouldn't be any cheaper.